Abstract
The ease with which explosives detonate on receiving a sharp blow or shock is of practical importance in determining manufacturing precautions and safety in handling, and also in deciding what initiators can be used. Physical tests on sensitiveness have hitherto imitated either manufacturing or service conditions as closely as possible. With any one physical test, such as that of the impact machine (cf. part III (1)), it is possible to arrange explosives in a scale of sensitiveness. The order of sensitiveness in a scale determined in any one way may be quite different from the order determined in other ways, but owing to the empirical nature of the tests it is often difficult to explain why anomalies occur. Results in accordance with each other are, however, obtained in many cases. Progress in synthetic organic chemistry has increased the range of possible explosives to such an extent that some more scientific information on sensitiveness would be most useful in orienting future developments. Various developments in the experimental knowledge on the subject are discussed in the following sections.